The case -- involving a girl named Angelica by her mother and Megan Marie by the New Britain couple -- has resulted in an emotional debate over the state's policies on adoption and parental rights. Earlier this week, about 3,500 people petitioned Blumenthal to take action.

But Blumenthal's appeal is expected to focus on a narrow legal issue: whether Judge John T. Downey of New Haven Superior Court misread state law when he allowed the mother to try to regain her rights as a parent 4 1/2 months after those rights had been terminated.

State child-welfare workers said they had believed the termination of rights was irrevocable after 20 days. The short time frame, they said, was important because hearings to terminate parental rights are frequently the last obstacle to adoptions. The longer the time available to appeal, the longer adoptions could be jeopardized, they said.

Blumenthal said his appeal was filed Friday, but he said little else. Confidentiality laws governing juvenile matters mean the course of the appeal will be secret until the court releases its decision.

The baby was born in New Haven June 26, 1991. The mother, Gina Pellegrino, 19, gave a false name at the hospital and vanished the same day. A month later, Downey terminated her parental rights, a legal move that, among other things, frees a child for adoption.

In October, the girl was placed with Cindy and Jerry LaFlamme, who planned to adopt her.

In mid-December, however, a lawyer for Pellegrino asked Downey to reconsider his decision. He agreed, citing two statutes he said allowed him to reconsider the case beyond the 20-day limit familiar

to workers at the Department of Children and Youth Services.

One law sets a four-month deadline for seeking to reopen civil court cases. Although the four months had passed, Downey said Pellegrino had attempted to challenge the termination judgment within four months, but had been told by the children and youth department that she could not.

The law also allows a judge to reopen a civil case in which the court has continuing jurisdiction. Downey said he was given that jurisdiction by another law that requires annual court reviews of the state's plans for the children of those whose parental rights have been terminated.

Blumenthal will argue that Downey erred in his application of both laws. Pellegrino's attorney, Angelica Allen, said she doubts the appeal will succeed